Timing devices and arrangements



16, 1966 H. J. WEIR 3,266,794

I TIMING DEVICES AND ARRANGEMENTS Filed March 25. 1965 A TTO/Z NE Y5 United States Patent M 3,266,794 TllMlNG DEVKCES AND ARRANQEMENTS Henry John Weir, Sedhury, Shepstow, England, assignor to British Laundry Machinery Company, Limited, Wembiy Park, Middlesex, England, a British company Filed Mar. 25, 1965, er. No. 442,656

Claims priority, application Great Britain, Apr. 2, 1964,

9 Claims. (Cl. 270-81) The invention relates to timing devices and arrangements for timing a machine operation on an article carried on a conveyor.

Particular application for the invention is found in timing the folding operations in laundry folding machines of the kind having a moving conveyor situated to receive laundry articles as they issue from an ironer. In such machines the articles (usually fiat-work such as sheets, towels etc.) may be folded in one or both of two ways. In the first way the leading edge of the article may be clamped between a pair of jaws, either before or after it reaches the conveyor, and the jaws are raised to allow the remainder of the article to be carried forward on the conveyor. The jaws are then opened to drop the held edge, usually so that it falls on the trailing edge of the article which is thereby folded in half.

The second way of folding is by tucking the article across its width at a predetermined line (half way along the article for folding in half) and inserting the tuck between two contacting rollers which rotate and draw the article through.

Since the conveyor moves rapidly and the folds are required to be made with an accuracy of 1% or so the timing of the clamping of the jaws or the operation of the tucking device is critical. These machine operations can be initiated by photo-electric devices or mechanical microswitches in the conveyor bed and responsive to the passage of the article to be folded. It is inconvenient, however, to arrange these devices at the place where the folding operation is to be performed. Thus it is desirable to arrange a switch device ahead of the folding position and have a delay between the actuation of the switch device and the operation of the folding device. Timing delay devices hitherto proposed for this purpose have included electronic and electro-mechanical devices which have been complex, unreliable and suffered from the further disadvantage that the delay was not related to the article speed. Thus unless complicated precautions were taken to en sure a constant machine speed despite variable loading, errors resulted. One object of the present invention to overcome these disadvantages.

Where, in the second-mentioned way of folding articles, the lengths of the articles to be folded are unknown and may vary from one to the next it is necessary to determine the appropriate delay in accordance with the length of the article. The present invention further seeks to provide a simple device for performing this additional function, the use of which does not necessitate extensive measures to stabilise the speed of the conveyor.

According to one aspect of the invention there is provided a timing device for timing a machine operation on the half-way point of an elongate article of unknown length carried on a conveyor wherein there are two sensors, one being adapted to give an output signal in response to the passage past one point of the trailing edge of the article, and the other sensor being adapted to give an output signal in response to the passage past another point, further along in the direction of travel of the article, of the leading edge of the article, the device comprising first and second drive members driven to rotate in synchronism with the conveyor; first and second engagement 3,2653% Patented August 16, 1966 members engageable respectively and independently with the peripheries of the first and second drive members to be driven in the same direction as each other, the second engagement being driven by the second drive member at twice the speed of the first engagement member when driven by the first drive member; means for engaging the first engagement member with the first drive member in response to the first occurring of two signals, thereby moving the first engagement from a rest position, the second engagement member being then entrained with the ond engagement member being then entrained with the fir first so as to be driven at the same speed thereby; means for engaging the second engagement member with the second drive member in response to the second occurring of said two output signals, and simultaneously disengaging the first engagement member from the first drive member, the first engagement member thereby returning to its rest position; and a switch arranged to be actuated by the second engagement member, when driven far enough, to initiate said machine operation.

Although the invention may be applied to machine operations other than laundry folding a preferred application of the invention is to laundry folding.

According to a further aspect of the invention a timing device arrangement for folding laundry articles comprises a conveyor having a belt which is carried forward over the top and back beneath a conveyor drum at one end of the conveyor; a :pair of folding rollers having horizontal axes, arranged one above the other in contact with each other so as to rotate in opposite directions and disposed first beyond said end of the conveyor and slightly below the level of said drum; a horizontal set of fingers opposite the junction of the folding rollers; a solenoid arranged to project the fingers between the rollers on energisation; first and second switches arranged near the upper run of the conveyor to be actuated respectively by the passage of the trailing edge and the passage of the leading edge of the article to be folded, the second switch being nearer said end of the conveyor than the first, each switch giving an output on actuation; first and second drive members driven to rotate in synchronism with the conveyor; first and second engagement members engageable respectively and independently with the peripheries of the first and second drive members to be driven in the same direction as each other, the second engagement member being driven by the second drive member at twice the speed of the first engagement member when driven by the first drive member; means for engaging the first engagement member with the first drive member in response to the first occurring of said output signals, thereby moving the first engagement member from a rest position, the second engagement member being then entrained with the first so as to be driven at the same speed thereby; means for engaging the second engagement member with the second drive member in response to the second occurring of said output signals and simultaneously disengaging the first engagement member from the first drive member, the first engagement member thereby returning to its rest position; and a switch arranged to be actuated by the second engagement member, when driven far enough, to energise said solenoid, the arrangement being such that the article is conveyed over said end of the conveyor to fall between the fingers and the folding rollers and actuation of the solenoid is eifected so that the half-way point of the article is tucked by the fingers between the folding rollers and the article is drawn therethrough.

Preferably the or each drive member is a wheel mounted with its axis horizontal and on engagement with the 'wheel the respective member is moved upwards, the or each engagement member being substantially a sector of a disc pivoted at the disc centre about a horizontal 9 axis, the arcuate edge of the engagement member being engageable with the edge of the respective wheel.

Conveniently the or each engagement member is carried on a 'lever arm pivoted at one end and coupled at the other end with operating means operable to pivot the arm and thereby engage the engagement member with the or each respective drive member. Said operating means may be hydraulic or pneumatic, comprising a cylinder and piston, but is preferably a solenoid.

The second drive member has preferably twice the periphery and, when driven, twice the peripheral speed of the first. The two engagement members are preferably moved by the drive members upwards against their weight and the second engagement member is moved by the first by resting on a part or an extension thereof, the arrangement being such that on engagement of the second engagement member with the second drive member the first engagement member is disengaged from the first drive member and allowed to drop.

There follows a description of two embodiments of the invention made with reference to the accompanying drawings, of which:

FIGURES l and 2 are side and end elevations respectively of a timing device according to the invention; and

FIGURE 3 is a diagram showing further parts, in addition to those of FIGURES 1 and 2, of an arrangement according to the invention.

FIGURES l and 2 show a timing device which ensures that a machine operation is effected on the half-way point of an elongated article. The device is similar to the FIGURE 1 device but has two engagement members constituted by two resin-bonded fabric board members 1a, 1b, each shaped substantially as a sector of a circle, pivoted about a common axis passing through the centers of the circles on which axis lie respective pivots 2a, 2b. Engagement members 1a, 1b are carried respectively on lever arms 3a, 3b which are pivoted respectively at 4a, 4b and coupled at their other ends through springs 5a, 5b with solenoids 6a, 612. On energization of the respective solenoid member 1a or -1b is drawn against the edge of a drive member constituted by a wheel 7a or 7b respectively, the two drive member wheels being mounted on a common axis to rotate together in the direction shown by the arrow in synchronism with the conveyor with which the device is associated, being geared thereto. The conveyor is shown schematically at C and the gearing at G. Wheel 7b is twice the diameter of wheel 7a and member 1b is correspondingly slightly smaller in radius than member 1a. A microswitch 8a is arranged at the upper end of the path of member 1b so that it is actuated by contact therewith. The starting point for the members 1a and 1b is determined by an adjustable stop 9a on which they normally rest.

On energisation of solenoid 6a member 1a engages wheel 7a and is drawn upwards and the arrangement is such that member 1b is also drawn upwards at the same rate. This is effected by a laterally extending pin 10 mounted in member 1a and accommodated in a recess 11 in member 1b. This arrangement is not reciprocal in that if solenoid 6b is energised only member 1b is drawn upwards, and this at twice the speed that member 1a is drawn upwards.

A typical operating sequence for the arrangement of FIGURES 2 and 3 will be described in conjunction with its application to an arrangement for folding laundry articles in 'half, FIGURE 4 showing schematically the relevant parts of such an arrangement. With reference to FIGURE 4 the machine has a conveyor 12 continuously moving in the direction indicated by the arrow on the conveyor wheel 13. The article 14 to be folded is allowed to roll off the conveyor and hang before two counter rotating and contacting rollers 15. When the half-way point of the article is mid-way between the rollers 15 a solenoid 16 is energised to poke forward an appropriately positioned ticking plate 17 and thereby tuck the mid-line of the article between the rollers 15. The article is thereby drawn, folded, between the rollers.

To effect the timing of energisation of solenoid 16 for an article of unknown length the device of FIGURES 2 and 3 is used in conjunction with two micro-switches 18, 19 situated over the conveyor and actuated respectively by the passage of the leading edge and the passage of the trailing edge of the article. The spacing between switches 18 and 19 is half the maximum length of an article which the machine is designed to fold and the distance in the path of the articles from the switch 18 to the folding part at plate 17 is as short as practicable. In an arrangement as shown where the articles come in part off the conveyor before folding this latter distance may be typically 6 and the distance between switches 18 and 19 2 ft., thereby catering for articles of maximum length 4 ft.usually 8 ft. sheets already folded in half.

When the leading edge of the article passes switch 19 nothing happens except that it is ensured that the circuitry is set for operation. Passage of the leading edge past switch 18 actuates this switch which thereby energises solenoid 6a (FIGURE 2). Members 1a and 1b move upwards at a speed proportional to the conveyor speed. When the trailing edge of the article passes switch 19 this switch is actuated and solenoid 6b energised and solenoid 6a simultaneously de-energised thereby. Member 1b thus further proceeds upwards on its own at twice its former speed, still in proportion to the conveyor speed. Finally member 1b strikes the microswitch 8a which energises solenoid 16 and effects the folding operation. Solenoid 6b is de-energised and member 1b allowed to drop. The distance between stop 9a and switch 8a is so adjusted that solenoid 16 is energised as the half-way point of the article passes plate 17.

Switches 18 and 19 and solenoids 6a and 6b are interconnected in such a way that the first one which is actuated energises solenoid 6a and the other one de-energises solenoid 6a and simultaneously energises solenoid 6b (it being remembered that actuation of switch 19 is by the trailing edge and not the leading edge of the article). In this way the measuring and delay operation above described is effected even for articles which are less in length than the distance between switches 18 and 19.

The interlocking of the members '14: and 1b by pin 10 and recess 11 offers the advantage that member 1a can be dropped to its starting position before member 1b has finished the measuring and delay operation and thus before the article has been folded. This allows the measurement of the next article by upward movement of member 1a to begin even before the preceding article is folded and so allows for rapid processing of articles. When the folding operation has been initiated for the preceding article the member 1b is dropped only to the position of member 1a and the measuring operation for the next article proceeds as normal.

The invention is not restricted to the details of the foregoing description with reference to the drawings. For example, the movable members need not be sector shaped but may be slides mounted to slide up the lever arms by contact with the rotary wheel. Interlocking in this cas may be by an arm from one member projecting underneath the other. The lever arms need not be operated by solenoids, but by hydraulic or pneumatic pistons and cylinders, the switch or trigger devices on the conveyor bed being appropriate to the system used, and the return of the members to the start position need not be by gravity but instead springs may be provided if it is desired to mount the members to move horizontally. The drive members may be constituted by, instead of wheels, moving belts.

I claim:

1. A timing device for timing a machine operation on the half-way point of an elongate article of unknown length carried on a conveyor wherein there are two sensors, one being adapted to give an output signal in response to the passage past one point of the trailing edge of the article, and the other sensor being adapted to give an output signal in response to the passage past another point, further along in the direction of travel of the article, of the leading edge of the article, the device comprising first and second drive members driven to rotate in synchronism with the conveyor; first and second engagement members engageable respectively and independently with the peripheries of the first and second drive members to be driven in the same direction as each other, the second engagement member being driven by the second drive member at twice the speed of the first engagement member when driWen by the first drive member; means for engaging the first engagement member with the first drive member in response to the first occurring of two of said output signals, thereby moving the first engagement member from a res-t position, the second engagement member being then entrained with the first so as to be driven at the same speed thereby; means for engaging the second engagement member with the second drive member in response to the second occurring of said two output signals, and simultaneously disengaging the first engagement member from the first drive member, the first engagement member thereby returning to its rest position; and a switch arranged to be actuated by the second engagement member, when driven far enough, to initiate said machine operation.

2. A timing device arrangement for holding laundry articles, the arrangement comprising a conveyor having a belt which is carried forward over the top and back beneath a conveyor drum at one end of the conveyor, a pair of folding rollers having horizontal axes, arranged one above the other in contact with each other so as to rotate in opposite directions and disposed just beyond said end of the conveyor and slightly below the level of said drum; a horizontal set of fingers opposite the junction of the folding rollers; a solenoid arranged to project the fingers between the rollers on energisation; first and second switches arranged near the upper run of the conveyor to be actuated respectively by the passage of the trailing edge and the passage of the leading edge of the article to be folded, the second switch being nearer said end of the conveyor than the first, each switch giving an output on actuation; first and second drive members driven to rotate in synchronism with the conveyor; first and second engagement members engageable respectively and independently with the peripheries of the first and second drive members to be driven in the same direction as each other, the second engagement member being driven by the second drive member at twice the speed of the first engagement member when driven by the first drive member; means for engaging the first engagement member with the first drive member in response to the first occurring of said output signals, thereby moving the first engagement member from a rest position, the second engagement member being then entrained with the first so as to be driven at the same speed thereby; means for engaging the second engagement member with the second drive member in response to the second occurring of said output signals and simultaneously disengaging the first engagement member from the first drive member, the first engagement member thereby returning to its rest position; and a switch arranged to be actuated by the second engagement member, when driven far enough, to energise said solenoid, the arrangement being such that the article is conveyed over said end of the conveyor to fall between the fingers and the folding rollers and actuation of the solenoid is effected so that the half-way point of the article is tucked by the fingers between the folding rollers and the article is drawn therethrough.

3. A device as claimed in claim 1 in conjunction with a laundry folding machine, said machine operations being a folding operation performed on a laundry article carried on a conveyor of the machine.

4. A device as claimed in claim 1 wherein each drive member is a wheel mounted with its axis horizontal and on engagement with the wheel the respective member is moved upwards.

'5. A device as claimed in claim 4 wherein each engagement member is substantially a sector of a disc pivoted at the disc centre about a horizontal axis, the 'arcuate edge of the engagement member being engageable with the edge of the respective wheel.

6. A device as claimed in claim 5 wherein each engagement member is carried on a lever arm pivoted at one end and coupled at the other end with operating means operable to pivot the arm and there-by engage the engagement member with each respective drive member.

7. A device as claimed in claim 6 wherein each operating means is a solenoid.

8. A device as claimed in claim 1 wherein the second drive member has twice the periphery and, when driven, twice the peripheral speed of the first.

9. A device as claimed in claim 1 wherein the two engagement members are moved by the drive members upwards against their weight and the first engagement member has an extension thereon, the second engagement member being moved by the first by resting on a part or an extension thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,516,454 7/1950 Doran 270- 2,743,920 5/ 1956 Petre 270-80 3,154,726 10/1964 McClain 27081 EUGENE R. CAPOZIO, Primary Examiner. NELSON M. ELLISON, Assistant Examiner. 

1. A TIMING DEVICE FOR TIMING A MACHINE OPERATION ON THE HALF-WAY POINT OF AN ELONGATE ARTICLE OF UNKNOWN LENGTH CARRIED ON A CONVEYOR WHEREIN THERE ARE TWO SENSORS, ONE BEING ADAPTED TO GIVE AN OUTPUT SIGNAL IN RESPONSE TO THE PASSAGE PAST ONE POINT OF THE TRAILING EDGE OF THE ARTICLE, AND THE OTHER SENSOR BEING ADAPTED TO GIVE AN OUTPUT SIGNAL IN RESPONSE TO THE PASSAGE PAST ANOTHER POINT, FURTHER ALONG IN THE DIRECTION OF TRAVEL OF THE ARTICLE, OF THE LEADING EDGE OF THE ARTICLE, THE DEVICE COMPRISING FIRST AND SECOND DRIVE MEMBERS DRIVEN TO ROTATE IN SYNCHRONISM WITH THE CONVEYOR; FIRST AND SECOND ENGAGEMENT MEMBERS ENGAGEABLE RESPECTIVELY AND INDEPENDENTLY WITH THE PERIPHERIES OF THE FIRST AND SECOND DRIVE MEMBERS TO BE DRIVEN IN THE SAME DIRECTION AS EACH OTHER, THE SECOND ENGAGEMENT MEMBER BEING DRIVEN BY THE SECOND DRIVE MEMBER AT TWICE THE SPEED OF THE FIRST ENGAGEMENT MEMBER WHEN DRIVEN BY THE FIRST DRIVE MEM- 